title: Ranking relative hydrogen-bond strengths in hydroxybenzoic acids for crystal-engineering purposes.
abstract: Systematic co-crystallizations resulting in a total of six new crystal structures involving either 3-hydroxy- or 4-hydroxybenzoic acid, complemented by calculated molecular electrostatic potential surfaces and existing structural data, have shown that in a competitive molecular recognition situation, the -OH moiety is a more effective hydrogen-bond donor than the -COOH moiety which, in turn, highlights that electrostatic charge can offer more useful guidance than acidity for predicting competitive hydrogen-bond preferences.
authors.affiliation: Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, KS 66506-0401 (USA), Fax: (+1) 785-532 6666. aakeroy@ksu.edu.
authors.forename: Christer B
authors.initials: CB
authors.lastname: Aakeröy
authors.forename: Kanishka
authors.initials: K
authors.lastname: Epa
authors.forename: Safiyyah
authors.initials: S
authors.lastname: Forbes
authors.forename: Nathan
authors.initials: N
authors.lastname: Schultheiss
authors.forename: John
authors.initials: J
authors.lastname: Desper
keywords: co-crystals; crystal engineering; hierarchy; hydrogen bonding; intermolecular interactions